Weekly Weather: Wetter and cooler pattern to continue this week

Good morning and welcome to my weekly weather report on the immediate past, present and future of weather in the Bayou City.

PAST

After a very dry start to July, the Houston region finally began seeing a pattern change this weekend, as an upper-level low pressure system sparked an already moist atmosphere to produce widespread showers.

On Sunday, the storms, which caused power outages in northwest Harris County, brought heavy rainfall to the west and north of downtown Houston. Here’s a rainfall accumulation map:

Rainfall accumulation map for the last 48 hours. (NWS)

The rain is most welcome as the entire region has sunk back into a drought, with most of the Houston metro area experiencing a “severe” drought, according to the U.S. Drought Monitor. In the next section, I’ll discuss how long this wetter pattern should hang around.

The aforementioned upper-level low pressure system, over central Oklahoma, will be in the best position today to deliver rainfall across the metro area, say forecasters with the Houston/Galveston office of the National Weather Service.

Although the low-pressure system will move off to the west later today and on Tuesday, it should leave a very moist atmosphere in its wake, allowing for at least a chance of rain showers most days this week, especially because high pressure isn’t expected to immediately replace it.

Weather Prediction Center forecast for rain accumulation during the next five days. (Weather Bell)

The lack of high pressure along with clouds and rain chances should also keep a lid on daytime temperatures this week, with highs likely to rise only to about 90 degrees through mid week, and perhaps into the low- and mid-90s by Friday and the weekend as partly sunny skies return.

The bottom line is that the work week looks to be cooler with a continued chance of rainfall. That’s just what the doctor ordered for mid-July.

This is typical for July, which is often a relatively calm month before the peak of the Atlantic hurricane season comes in August and September.

SUMMARY

My rating scale for this week’s weather goes from 0 to 9, the rank given to Matt Schaub by Ron Jaworski, as in he believes Schaub is the 9th best quarterback in the NFL.

My number: 7.9.

Finally, if you want several daily updates on weather, please “like” my SciGuy Facebook page. It’s the best place for multiple daily updates on our weather, delivered right to your news feed.

FINE PRINT

As always, thank you to the fine professionals at the National Weather Service for the information and data that make this weekly blog entry possible. Also, bear in mind there’s always uncertainty in weather forecasting, particularly the timing and intensity of precipitation.

Finally, after a week of empty promises, it was raining at my house in Dickinson when I left for work. Hopefully, I’ll get enough this week to get my grass to start growing again. The cooler temps are good, too.

Eric was off last week and not reporting as usual, so it’s difficult for me to see the forensics on this rain event, which doesn’t seem to have been predicted.

On July 11, Galveston County Daily News published a weather blog post titled “Searching for that elusive rainfall” and concluding “we are going to need some real luck to see any meaningful rains over the next week or two”. In other words, it was looking very unlikely that we’d have any rain whatsoever.

But by July 14, all heck was breaking loose in terms of rainfall, and it continues to look as if we will get more of it.

The rain is great news, but I sure wish we had better predictive capability even three days out. It’s high summer travel season and I’m shuttling an unaccompanied minor child back and forth to IAH and suddenly I need contingency plans for thunderstorm-driven delays whereas I had assumed based on weather reports that there would be no such disruptions… Ugh.

This event showed up in forecast packages nearly two weeks ago. There is a very unusual SW’ward moving low passing just north of us bringing in a backwards front. With high pressure to our west the winds are blowing from the SE bringing in lots of cool moisture off the gulf. The only thing lacking for a major flood event is a trigger to set off the storms. Hard to predict outflow boundaries and the sea breeze are the only triggers.

Keith, if this was predicted two weeks ago, I wonder if the possibility fell into the category of indecipherable chatter, because I had motivation to monitor the forecasts and I just didn’t see anything even remotely conclusive (and neither did GCDN, obviously).

Maybe it’s analogous to the difficulty in spotting terrorist acts: hindsight is always 20/20, and once you know the identity of the perp, it then becomes easy to back-trace a trail of evidence. But try in advance to separate out the real perp from the hundred thousand or so random events and Trojan horses and it becomes impossible. Statistically, perhaps there’s always an accurate weather forecast out there somewhere, but separating it from its inaccurate competitors often doesn’t seem to be achievable by the average news consumer.

I think it is worth reminding you (and others) this so called “wet event” -do you realize roughly 70% of the Houston/Galveston metro area received less than .25 inches of rain? So despite the perception of it all of the sudden being a wet period (some people pointed out they got hit not once but twice with heavy rains) the majority of the area received very little in the way of precipitation over the last few days. Go back and check out Eric’s map.

Eric, it’s good to have you back. Finally some good news with the weather, although we got absolutely no rain yesterday in Magnolia! I was watching the radar all day in anticipation because there was a huge line of rain moving down from Dallas and all of a sudden it stopped right around Bryan and stalled there. Storms popped up off the coast and moved into Houston, but that did nothing for us. Left us high and dry. Looking at the current radar I’d like to know what is our best shot at rain over in Tomball, Magnolia, Waller area? The rain to our north or the one coming in from the coast?

Last night was the first decent rain we’ve seen in the Humble/Kingwood area in well over a month. After last week’s tropical system turned into a total bust it marked the third or fourth system in a row that failed to produce much convection south of Cleveland. Why have so many systems (until now, thankfully) had such a difficult time producing storms around the Houston/Galveston area?

Hi Eric, can you please tell me why there seems to be some sort of no-rain bubble over the Lake Conroe area?? We didn’t get a drop all weekend except we did get a sprinkle overnight. Today, the rain is all around us! This bubble has persisted for months now, and I’m really wondering what is going on; I’ve never seen anything like it and I’ve lived here all my life.